Sun Java 6 packages are being removed from Ubuntu in the near future for the
following reasons:

As of August 24th 2011, Canonical no longer have permission to redistribute
new Java packages as Oracle has retired the “Operating System Distributor
License for Java”.

Oracle has published an advisory about security issues in the version of
Java currently in the partner archive. Some of these issues are currently
being exploited in the wild.

Due to the severity of the security risk, Canonical released a security
update for the Sun JDK browser plugin which disables the plugin on all machines.

In the near future, Canonical will remove all Sun JDK packages from the
Partner archive. This will be accomplished by pushing empty packages to
the archive, so that the Sun JDK will be removed from all users machines
when they do a software update. Users of these packages who have not
migrated to an alternative solution will experience failures after the
package updates have removed Oracle Java from the system.

Update Monday 16th January 2012

Update Friday 13th January 2012

My Java PPA has been disabled by Canonical, possibly because they violate the Ubuntu CoC and PPA terms of use, as Jef Spaleta noted in the comments below, although I’ve had no communication from Canonical at this time. I’m preparing an alternative solution, for those of you who need Sun Java 6, that doesn’t violate and copyrights, CoCs or terms of use. A new blog post will be made when that alternate solution is available.

My personal motivations for creating this PPA are as follows:

I require Sun Java 6 for two enterprise applications we use at work. OpenJDK is not fully compatible.

I require Sun Java 6 for two desktop applications at home (so does my father-in-law). OpenJDK not compatible in one instance and not fully compatible in the other.

I require Sun Java 6 browser plugin for a web applications I use at home. OpenJDK is not compatible.

A friend of mine requires Sun Java 6 for building AOSP from source. OpenJDK is not compatible.